Voluntary musical imagery in music practice : contextual meaning, neuroscientific mechanisms and practical applications

This is a self-archived version of an original article. This version may differ from the original in pagination and typographic details. Author(s): Title: Year: Version: Copyright: Rights: Rights url: Please cite the original version: CC BY 4.0 https://creativecommons.org/licenses/by/4.0/ Voluntary musical imagery in music practice : contextual meaning, neuroscientific mechanisms and practical applications © 2024 Meng and Luck Published version Meng, Chen; Luck, Geoff Meng, C., & Luck, G. (2024). Voluntary musical imagery in music practice : contextual meaning, neuroscientific mechanisms and practical applications. Frontiers in Psychology, 15, Article 1452179. https://doi.org/10.3389/fpsyg.2024.1452179 2024 Frontiers in Psychology 01 frontiersin.org Voluntary musical imagery in music practice: contextual meaning, neuroscientific mechanisms and practical applications ChenMeng 1* and GeoffLuck 2 1 Department of Music, Art, and Culture Studies, University of Jyväskylä, Jyväskylä, Finland, 2 Centre of Excellence in Music, Mind, Body and Brain, Department of Music, Art, and Culture Studies, University of Jyväskylä, Jyväskylä, Finland Practice is acknowledged as a crucial facilitator for musicians to achieve performance excellence. Despite the rich literature on incorporating musical imagery intentionally to improve one’s practice efficacy, limitations remain in the understanding of voluntary musical imagery (VMI) in the context of musical practice. Therefore, our aims in this review are threefold. First, weenriched the interpretation of VMI in the context of music practice through the lens of embodied cognition. Second, weintegrated neuroscientific findings to elucidate how the deliberate use of musical imagery parallels physical practice in effectiveness. Third, wesynthesize work on the application of VMI in enhancing musical learning from both theoretical and practical perspectives. By providing an integrated overview of voluntary musical imagery, wehighlight gaps in the literature and encourage further research on (1) the impact of embodied experiences on VMI formation, (2) optimal imagery content and ratio combination to establish a personalized intervention protocol for more effective musical pedagogy, and (3) on physiological measures to access VMI effectiveness. Additionally, wehighlight the crucial implications of VMI for researchers, performers, and music educators. KEYWORDS music practice, voluntary musical imagery, embodied music cognition, neural activation, functional equivalence, mental practice, practice strategies, PETTLEP model 1 Introduction Musicians, defined as individuals with extended periods of musical training (Zhang etal., 2020), are generally aware that achieving performance excellence requires consistent and extensive effort (Clark etal., 2014; Gregg etal., 2008). Among the diverse ways of improving one’s level of performance, efficient practice strategies have been recognized as crucial in facilitating development of musical expertise (Ericsson etal., 1993; Platz etal., 2014; Sloboda etal., 1996). Since the turn of the millennium, the number of studies concerning the effectiveness of music practice has expanded significantly (How etal., 2022; Miksza, 2011). Researchers from diverse disciplines, including but not limited to music education, performance science, music psychology, and neuroscience, have acknowledged the crucial role of efficient practice strategies in enhancing expertise. Among these strategies, imagery-focused approaches have been identified as particularly beneficial (e.g., Driskell etal., 1994; Ericsson, 1998; Macnamara etal., 2014). OPEN ACCESS EDITED BY Graham Frederick Welch, University College London, UnitedKingdom REVIEWED BY Steven Morrison, Northwestern University, UnitedStates Kristian Steenstrup, The Royal Academy of Music, Denmark *CORRESPONDENCE Chen Meng [email protected] RECEIVED 20 June 2024 ACCEPTED 29 October 2024 PUBLISHED 11 November 2024 CITATION Meng C and Luck G (2024) Voluntary musical imagery in music practice: contextual meaning, neuroscientific mechanisms and practical applications. Front. Psychol. 15:1452179. doi: 10.3389/fpsyg.2024.1452179 COPYRIGHT © 2024 Meng and Luck. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. TYPE Review PUBLISHED 11 November 2024 DOI 10.3389/fpsyg.2024.1452179 Meng and Luck 10.3389/fpsyg.2024.1452179 Frontiers in Psychology 02 frontiersin.org Imagery refers to the inner conscious process of representing or recreating multifaced sensory information (e.g., auditory, visuomotor, etc.) in the mind, particularly in the absence of the external stimulus (Cumming and Williams, 2012; Kosslyn etal., 2001). Grounded upon the nature of imagery as a multisensory cognitive process, research has indicated that individuals are capable of mentally visualizing, hearing, feeling, and rehearsing real-world experiences without actual physical actions (Keller, 2012; Wöllner and Williamon, 2007). Many researchers have investigated the phenomenon of imagery related to music. One common discovery is that individuals, regardless of their level of musical training, can “hear” melodic tunes in their minds initiated spontaneously (e.g., Liikkanen and Jakubowski, 2020). This phenomenon has been termed involuntary musical imagery (INMI; Williamson and Jilka, 2014) or, more colloquially, an “earworm” (Williams, 2015), in which individuals hear music in their mind’s ear persistently and intrusively without additional effort. Interestingly, however, research has also shown that people are capable of intentionally using musical imagery to mentally rehearse specific music features (e.g., pitch, loudness, and timbre; Cotter, 2019), as well as the physical movement required to create the sound (Bailes, 2009; Godøy, 2022; Holmes, 2005). For example, by interviewing four visually impaired and one fully sighted Western classical pianists about their multifaceted mental experience during music learning and performance, Herbst and Van Zyl (2022) discovered that all participants were able to mentally “feel” the visuospatial chord without the keyboard, “recognize” colors via tonality, and experience elicited emotions during the performance and listening. While deliberately utilizing musical imagery for performance enhancement has garnered considerable interest within the academic community (e.g., Diana, 2016; Hatfield and Lemyre, 2016; Vilnite and Marnauza, 2023), its interpretation and effect in musical practice varies considerably. To date, most research has been conducted in parallel with individual studies addressing specific aspects of the topic, such as improving memorization (Bernardi etal., 2012), enhancing ensemble coordination (Keller and Appel, 2010), refining performance expressivity (Woody, 2002), and controlling music performance anxiety (Hoffman and Hanrahan, 2012). As a result, a number of issues remain, such as the terminology of musicians’ deliberate imagery usage and the relationship between imagined and actual execution. Additionally, the theoretical frameworks and practical efficacy of voluntary imagery usage in musicians’ practice have yet to becomprehensively synthesized (How etal., 2022). Here, weexplore the existing literature to compare and contrast the theoretical exploration and empirical examination of the deliberate usage of musical imagery within the fields of music education, cognitive neuroscience, and psychology studies. Furthermore, weaim to enrich the understanding of voluntary musical imagery in the context of music practice, clarify the neuroscientific mechanisms behind the benefits of deliberate musical imagery in music practice, and synthesize studies on the intentional use of musical imagery to enhance musical learning from both theoretical and practical perspectives. In so doing, weuncover gaps in knowledge and areas for future empirical development and offer insights into imagery guidance for researchers, performers, and music educators. 2 Contextual understanding of voluntary musical imagery 2.1 Musical imagery Recognized as a complex, multifaceted phenomenon, musical imagery has evolved significantly in scientific examination over the past century (Clark etal., 2012). In early studies, musical imagery was viewed as an inner auditory capacity (Seashore, 1919), via which talented musicians could mentally represent and utilize tones and chords (Hubbard and Stoeckig, 1988) or imagine and reproduce musical sounds and sequences (Janata and Paroo, 2006). In the 1970s, Edwin Gordon introduced the concept of ‘audiation’ to describe this process of mentally recalling or comprehending previous musicalsounding experiences. He emphasized this cognitive skill as a prominent tool for music learning and pedagogy (Gordon, 1999, 2021). Later scholars from the music performance field enriched this auditory-only perspective, proposing that musical imagery is not merely a “tune in the brain” but comprises multimodal characteristics of musical performance (Bailes, 2006, 2007a), such as mentally experiencing the movement required to produce the musical sound (Bernardi et al., 2013), seeing music notations in the mind’s eye (Mongelli etal., 2017), and mentally predicting other performer’s action in musical ensemble cooperation (Keller and Koch, 2008). Grounded upon previous foundational exploration, Keller (2012) has defined musical imagery as: “a multimodal process by which an individual generates the mental experience of auditory features of musical sounds, and/or visual, proprioceptive, kinesthetic, and tactile properties of musicrelated movements, that are not (or not yet) necessarily present in the physical world” (p.206). Given the high frequency of musical imagery experience among student musicians (Bailes, 2007a), its activation and interpretation in the context of music practice has received increasing scientific interest. 2.2 Involuntary musical imagery and voluntary musical imagery In terms of typologies of musical imagery, most studies have focused on two significant dimensions (Cotter, 2019; Williams, 2015): involuntary musical imagery (INMI) and voluntary musical imagery (VMI). A handful of studies have considered a third dimension, described variously as “anticipatory imagery” (Keller, 2012; Liikkanen, 2012) or “involuntary but necessary corollaries of musical activity” (Bailes, 2006, p. 174), both referring to the evoked musical consciousness during performance or musical analysis (Bailes, 2006, 2007a, 2009). Given the dominance of INMI and VMI in the literature, it is these two dimensions wefocus on in this article. INMI is proposed as a mental phenomenon in which music spontaneously enters one’s conscious awareness repeatedly without any effort to create or maintain it (Liikkanen and Jakubowski, 2020; Müllensiefen etal., 2014; Williamson etal., 2012). Early studies of how INMI affects skilled musicians can betraced back to Agnew (1922), who examined autobiographic evidence from 10 renowned composers (including Mozart, Schubert, Tchaikovsky, and Robert Schumann). Agnew argued that, although highly individual characteristics of musical thoughts could Meng and Luck 10.3389/fpsyg.2024.1452179 Frontiers in Psychology 03 frontiersin.org bedistinguished between each composer, the compositional ideas that came to their mind were commonly in the form of INMI (Agnew, 1922). By employing experience-sampling forms to record student musicians’ inner musical consciousness via phone prompts six times a day for a week, Bailes (2006, 2007a) empirically demonstrated the high frequency of INMI occurrence in music students’ daily routines. Similar results have been demonstrated by Beaty etal. (2013) and Hyman etal. (2013), who further suggest that music students report experiencing INMI more frequently than their non-musical counterparts, indicating a correlation between musical training and the occurrence of INMI. However, the evidence is not uniformly consistent across all studies. Both Liikkanen (2012) and Williamson and Jilka (2014) found that individuals with higher music expertise appear to have a lower frequency of involuntary musical imagery. To further complicate matters, Beaman and Williams (2010) and Müllensiefen et al. (2014) did not find a significant relationship between INMI frequency and musicianship, while Floridou etal. (2015) and McCullough Campbell and Hellmuth Margulis (2015) reported mixed or negative results regarding the impact of musical training on INMI susceptibility. Recently, Liikkanen and Jakubowski (2020) conducted a comprehensive review of the empirical literature related to INMI from multiple viewpoints, including its maintenance, activation, personal differences, and content of representation. Despite INMI being well-evidenced as an essential cognitive component in everyday life circumstances, its influence and causal efficacy in music practice remain to befurther explored. 2.3 Meaning of voluntary musical imagery In contrast to INMI, some researchers have proposed that certain individuals, notably those with musical training, possess a higher capacity to consciously evoke and manipulate musical details without the presence of an external stimulus (e.g., Gregg etal., 2008; Holmes, 2005). For example, a study by Aleman etal. (2000) demonstrated that individuals with over 5 years of musical training possess enhanced musical imagery abilities, enabling them to outperform those with more limited musical training (i.e., less than 2 years) in tasks requiring the mental manipulation of musical and non-musical sounds. Further auditory research has identified specific aspects of musical imagery that skilled musicians can adeptly control mentally. These include reliving and adjusting the musical pitch (Janata and Paroo, 2006), loudness (Bishop etal., 2013), and instrumental timbre (Bailes, 2007b; Crowder, 1989; Halpern etal., 2004). With these capacities, individuals with greater levels of musical training are able to mentally rehearse their repertoire thoroughly before going on stage (Clark and Williamon, 2011; Freymuth, 2004) and mentally practice the music without touching the instrument (e.g., Davidson-Kelly etal., 2015). While the phenomenon of actively representing musical experiences mentally, in the absence of direct stimuli, is widely recognized, the terminology used to describe this process is not consistent across studies, being referred to variously as “voluntary musical imagery,” “volitional musical imagery,” or broadly as “musical imagery.” This inconsistency in terminology leads to confusion about what each term specifically means, complicating efforts to synthesize and compare findings across different studies. Additionally, the specific interpretation of this concept in music practice remains unclear. For instance, Williams (2015) defined VMI as the “musical experience that was called to mind through the active choice of the person in the absence of direct sensory instigation of that experience” (p.5), emphasizing the subjective intentionality of musical imagery when musicians employ it for their mental practice or composition. More recently, Godøy (2019, 2022) integrated music theory, phenomenology, and cognitive science to formulate the deliberate initiation and maintenance of musical images in minds as volitional musical imagery. Heargues that the intentional control or recreation of musical sound in the mind is triggered by the motions of sound production. This conceptualization emphasizes the role of motor cognition in engagement of musical imagery, where musicians can mentally hear or compose the music by visualizing the performing movements (for more detail, see Küssner etal., 2022). While Williams (2015) and Godøy (2019, 2022) provide valuable insights into understanding VMI, their interpretations have limitations. Specifically, although Williams highlights the conscious decision to recall musical imagery without sensory input, her definition may overlook the fact that the “music experience” for musicians is derived intensively from the physical sensations and movements during their extensive daily practice. By focusing solely on mental choice, Williams’ definition does not fully account for the role of embodied experience in forming and sustaining vivid musical imagery, such as the tactile feedback from an instrument, muscle memory developed through repetitive practice, and kinesthetic sensations of playing or singing (Steenstrup etal., 2021). This neglect of embodied aspects risks oversimplifying the richness of musicians’ imagery content. Similarly, while Godøy highlights volitional musical imagery as the dynamic interplay between motion imagery and auditory imagery, the focus on motor imagery alone may oversimplify the multi-sensory musical experience integral to musical performance and appreciation. As such, a gap exists that emphasizes the need for an interpretation of VMI that aligns with the unique requirements of musicians. To deepen our understanding of the deliberate use of musical imagery in the music context, weconsider it as voluntary musical imagery and propose a more comprehensive interpretation of musical imagery from the perspective of embodied music cognition in the context of music practice. That is, VMI is not merely an intentional mental representation or recreation of the musical performing experience but also an embodied phenomenon in which cognitive and physical processes are deeply interwoven. This interpretation of VMI aligns with the foundational principles of embodiment studies. Embodied research indicates that cognitive processes like thinking, perceiving, and understanding are formed by corporal interaction with the real-world environment (Varela etal., 1991; Varela F. J. etal., 2016; Leman and Maes, 2014). In the music context, Leman etal. (2018) describe embodied music cognition as the “cognition in perception” (Leman etal., 2018, p.748) – that cognitive processing of music, such as learning, recalling, and predicting, are formed by the interaction of our body with music (Dahl etal., 2023; Hashim etal., 2023). From this perspective, music imagery is integrally linked to the perception and bodily experiences of engagement with music (Leman, 2008; Niedenthal etal., 2005; Thompson and Luck, 2012). Music practice exemplifies this embodied perspective (Cox, 2016). For instance, Gebel et al. (2013) investigated the neural auditory-motor loop between trumpeters and pianists with long-term (c. 15 years) training. They found that the degree of auditory to motor Meng and Luck 10.3389/fpsyg.2024.1452179 Frontiers in Psychology 04 frontiersin.org cortical activation varied between the two groups of instrumentalists, and the cause of this cognitive processing difference was influenced by the physical and sensory systems developed through their contextspecific training. Similarly, Kajihara et al. (2013) examined the influence of musical expertise and pedagogical approaches on auditory-motor coupling. By asking non-musicians, conservatorytrained violinists, and pupils trained with either traditional and Suzuki methods to match pitches with mental finger-numbers, their study illustrated that experienced violinists and learners trained under the Suzuki method demonstrated significant pitch-to-finger mapping accuracy and speed. Their result suggests that the musical auditorymotor coupling ability is not innate but could beshaped by specific embodied pedagogy. These findings reinforce the idea that embodied training experiences profoundly shape skilled musicians’ mental representation (Godøy, 2003). Wilson (2002) divided embodiment into “online” and “offline” forms. Specifically, the “online” form indicates perceptual activities and cognitive processes that are directly tied to real-world interactions (Leman and Maes, 2014; Niedenthal etal., 2005), such as expressive musical intentions through body gestures (Thompson and Luck, 2012). On the other hand, “offline” embodiment refers to cognitive activities that occur without direct engagement with the environment, such as practice without auditory feedback. From this viewpoint, Jäncke (2012) employed scalp EEG and standardized low-resolution electrical tomography (sLORETA) to examine the dynamics of the auditory-motor system in piano performance. By examining six professional pianists’ performance with and without auditory feedback, they revealed a causative influence from the auditory cortex (AC) to the premotor cortex (PMC). This influence was found to persist significantly in the non-auditory condition, as well as during rest state. These findings revealed that pianists can activate these auditory-motor pathways even in the absence of physical performance. Recently, Klein etal. (2016) used high-density electroencephalography to evaluate whole-brain functional connectivity during resting states in both string players and non-musicians. Their results showed that similar brain regions activated during musical performance remain functionally connected even at rest. These studies demonstrate that intentional mental imagery has the capacity to embody real-world perception and re-experience it mentally without physical involvement. As such, the understanding of VMI was enriched from two complementary perspectives: the embodiment-imagery and the imagery-embodiment directions. Specifically, the “embodimentimagery” perspective illustrates the function of VMI as an “offline” simulation of multimodal real-world cognition (Bailes, 2019; Niedenthal etal., 2005). For example, musicians often report physically “feeling” the music even when they are merely imagining it, indicating that VMI involves simulating the physical actions associated with music production (Godøy and Jørgensen, 2001). This engagement suggests that music learners may enhance their understanding and execution of musical pieces by involving not only auditory representations but also motor executions during mental practice (Schiavio et al., 2014). Conversely, the “imagery-embodiment” direction offers insights into how VMI can facilitate physical music practice. By intentionally engaging in VMI, musicians can mentally rehearse their performances, which may reinforce the motor and auditory pathways involved in actual performance. To further advance our comprehension of VMI, wereview its neuroscientific exploration and practical application in musicians’ practice routines below. 3 Neuroscientific mechanisms of voluntary musical imagery Studies of VMI have garnered significant interest among neurocognitive scientists perhaps due to its features of prevalence in musicians’ mental practice and vividness in musical details (Zatorre, 2003; Zatorre and Halpern, 2005). Along with the evolution of neuroscientific technologies, researchers are able to deepen our understanding of VMI beyond behavioral and self-report experiments (Levitin and Grafton, 2016) via a range of experimental tools, such as magnetoencephalography (MEG), electroencephalography (EEG), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI). By employing such technologies, scholars have made valuable contributions to our understanding of VMI in terms of neural activation (e.g., Zatorre et al., 1996), differences compared to music perception (e.g., Herholz etal., 2012) and network correlations in the brain (e.g., Zatorre and Halpern, 2005). 3.1 Neural activation during VMI Early studies by Zatorre and Halpern (1993) demonstrated that musical imagery activates neural regions involved in auditory perception. Their research on patients with temporal-lobe excisions showed that imagining familiar tunes engages the same neural areas as actually hearing them. Later studies confirmed these results, with findings indicating that the auditory cortex is similarly activated during both mental imagery of music and actual music listening, even without external sound stimuli (Zatorre etal., 1996; Zatorre and Halpern, 2005). Previous fMRI studies of mental music evaluation tasks, such as pitch judgment (Zatorre etal., 1996), melodic extensions (Halpern, 1999), timbre recognition (Halpern etal., 2004) and tonal accuracy of imagined melodies (Herholz etal., 2008), have revealed that the secondary auditory cortex and the auditory association areas are largely activated and similarly overlapped between auditory imagery and auditory perception (Kosslyn etal., 2001). More recently, Regev et al. (2021) conducted a mapping study comparing the neural response between imagined and perceived music. fMRI scans of 25 participants instructed to deliberately imagine pre-memorized music extracts under tapping, no tapping and listening-only conditions revealed that imagery of musical melodies consistently activated participants’ early and associative auditory cortices. Specifically, the bilateral middle superior temporal plane (mSTP), areas overlapping with early auditory processing loci in Heschl’s gyri, anterior and posterior STP regions, and lateral parts of the right superior temporal gyrus (STG) all reflect the sensory regions activated during actual melody perception. These commonalities of the activation in brain regions reflect the equivalent neural function between VMI and the perception of music (Halpern and Overy, 2019; Levitin and Grafton, 2016). Neuroscientific studies have identified parallels in brain activation between executing and imagining music performance movements (see Lotze, 2013, for a review). For example, by analyzing fMRI data collected from 12 pianists performing Bartok’s Triolak in a right-hand-only task under live and imagery conditions, Meister et al. (2004) reported that bilateral parietal cortical activations in the supplemental motor area (SMA), premotor areas, Meng and Luck 10.3389/fpsyg.2024.1452179 Frontiers in Psychology 05 frontiersin.org the precuneus, and the medial part of Brodmann Area 40 had significant overlap in the two conditions. These findings highlight the rationale of action simulation, where motor imagery functions in an analogous neural mode with motor execution when voluntarily imagining musical movement (Keller, 2012; Lotze, 2013). Later studies found that the right superior parietal lobule (SPL) was highly engaged when performers reported mentally “seeing” their finger action while playing their instrument (BastepeGray etal., 2020; Lotze etal., 2003; Tanaka and Kirino, 2017). Moreover, the SMA, pre-SMA, and premotor cortex (PMC) were found to be actively engaged and particularly crucial for the coordination of imagined performance (Gelding et al., 2019; Halpern, 2001; Halpern etal., 2004; Tanaka and Kirino, 2017; also see Lima etal., 2016 for a review), especially due to their functions of movement generation, control, preparation, anticipation and sequencing arrangements (Tanaka and Kirino, 2017). This overlap of brain regions in both motor execution and imagery implies functionally equivalent possibilities for musicians, where voluntary imagery might reinforce physical practice by engaging the same neural circuits, potentially offering complementary benefits (Driskell etal., 1994). 3.2 Neural correlates of VMI Recent neuroscience research has revealed that diverse brain networks are activated during conscious musical imagery (BastepeGray etal., 2020; Halpern, 1999; Lotze, 2013; Lotze etal., 2003; Zatorre and Halpern, 2005). For example, Herholz etal. (2012) conducted fMRI examinations on 10 participants ranging from non-musicians to professionals to compare their neural activity while imagining and perceiving familiar tunes with lyrics. Regardless of their music expertise, an extended network, including the prefrontal cortex, supplementary motor area (SMA), intraparietal sulcus, and cerebellum, was activated during such imagery tasks. Musicians’ engagement with musical imagery has also been explored from a neuroscientific perspective. For instance, Langheim (2002) employed fMRI scans to demonstrate that a network involving the prefrontal cortex, parietal cortex, and lateral cerebellum was activated collectively in string musicians when engaging in intentional musical imagery. This discovery highlights VMI’s capacity to orchestrate the complex spatial and temporal aspects of musical performance, suggesting its critical role in enhancing musical execution through mental practice. Similar research has been conducted with vocalists. For instance, a study by Kleber etal. (2007) with 16 expert classical vocalists revealed that a correlated network encompassing frontal and parietal regions was activated during VMI. Moreover, Kleber etal. (2007) reported that professional singers employed different brain systems for imagined versus overt singing of Italian arias, with imagery involving a broader network of higherorder associative functions and more intense activation in the prefrontal and limbic areas. In light of these findings, it is evident that VMI activates diverse networks in the brain. Moreover, the identification of specific regions activated during imagery tasks further elucidates VMI’s potential mechanisms in supporting functions such as memory retrieval, tonal working memory activation, and mental monitoring (Ding et al., 2019; Herholz et al., 2012; Hubbard, 2010). Notably, Bastepe-Gray etal. (2020) discovered that the breadth of these networks and the depth of their activation during VMI varies depending on the method of mental representation employed. To investigate this, they conducted fMRI scans on seven oud players who employed three different mental practice strategies: eyes closed, eyes open, and following a musical score, with an eyes-open rest serving as a control. Their findings indicate that, while patterns of activation during VMI are consistent with prior neuroscientific research, the level of cortical activation is influenced by the chosen mental practice strategy. For example, despite all mental rehearsal strategies enhancing internal connectivity of the occipital lobe bilaterally, the strategy of vivid imagery with closed eyes resulted in the most widespread activation in these lobes. Given that different imagery models can trigger sensory and motor neural areas to differing extents, these results underscore the importance of designing context-specific VMI guidance based on a thorough understanding of the brain networks involved (Bastepe-Gray etal., 2020). 3.3 Differences between VMI and music perception While neuroscientists have explored the overlapping mechanism of imagined and actual perceived music, their inherent differences have also been highlighted. Studies have revealed that the primary auditory cortical regions have limited activation when recalling music consciously compared to music listening and are only engaged when participants imagine familiar songs with no lyrics (Kraemer etal., 2005; Levitin and Grafton, 2016; Regev etal., 2021). Similarly, the primary motor cortex is found to beless involved during imagery than in the actual movement execution (Lotze etal., 1999; Lotze etal., 2003). These different areas of brain activation, between imagining and actually perceiving music or executing movements, highlight differences in cortical processing of internal versus external stimuli. Additional differences in the sequence of neural activations between listening and imagining music have been proposed. Kosslyn etal. (2001) have stated that “mental imagery occurs when perceptual information is accessed from memory…perception occurs when information is registered directly from the senses” (p.635). Recent findings by Ding etal. (2019) provide additional evidence supporting differentiated cortical activity patterns during music perception and recall. By analyzing Electrocorticography (ECoG) data from 10 epilepsy patients, their study demonstrated distinct temporal sequences in neural activation. Specifically, during music listening, the initiation of cortical activity progresses from the sensory cortex to the frontal cortex, exemplifying a bottom-up approach. In contrast, music recall involves a reversed sequence, where activation begins in the frontal cortex and moves toward the sensory cortex, reflecting a top-down process. These finding contribute to our understanding of the directional dynamics of neural processing in auditory tasks. Additionally, they reveal that the unique induction mechanism of musical imagery, as a cognitive process, is able to retrieve long-term memory stored previously or reactivate the sensory regions of the brain (Halpern, 1999). Meanwhile, the participation of the frontal cortex also implies that imagining music voluntarily is a higher-level cognitive neural activity that involves multiple regions of the brain (Bastepe-Gray etal., 2020; Centanni etal., 2020). Meng and Luck 10.3389/fpsyg.2024.1452179 Frontiers in Psychology 06 frontiersin.org In summary, extensive research on VMI has uncovered an intricate neural mechanism underpinning musical imagery and perception, delineating the dynamic interplay among cognitive processes involved. Through the utilization of sophisticated neuroimaging techniques, scholars have elucidated the parallel cortical activation contents during music perception and VMI, discovered their constitutional differences, and underscored the critical role of the auditory and motor cortex in a musician’s imagery process. This equivalence in neural functioning provides a solid foundation for the use of VMI during mental practice, which might be integrated into physical practice routines as a personalized protocol, offering musicians an adaptable approach to their unique needs in skill acquisition and performance enhancement. 4 Applications of VMI: theoretical and practice perspectives 4.1 Voluntary musical imagery in musical practice: theory comparison Building upon the neuroscientific findings concerning the cortical overlap between imagined and actual practice execution, scholars from music psychology and pedagogy have discovered that expert performers, through the mental representation of specific performance details, can facilitate the planning and evaluation of potential actions and enable precise monitoring of and feedback for their performance (e.g., Ericsson, 1998). The theoretical frameworks that utilize VMI in achieving music improvement have focused on two pivotal theories: deliberate practice (DP) and self-regulation learning (SRL). 4.1.1 Deliberate practice theory Music practice is historically viewed as a structured and deliberate learning process aimed at enhancing musical abilities. Such perspectives are rooted in the seminal exploration of Ericsson etal. (1993). Derived through qualitative and quantitative analysis of the development of selected conservatory violinists, Ericsson and colleagues discovered the acquisition of expert-level excellence was associated with early-start, time-consuming, daily deliberate practice. Unlike general physical training, deliberate practice was defined as knowledge-driven, goal-oriented, and improvement-focused exercises (Ericsson, 1996, 1998; Ericsson and Harwell, 2019; Passarotto etal., 2022). This influential work shaped understanding of how expert-level skills in music are achieved not merely through hours of practice but through engaging in specifically-designed exercises (Mazur and Laguna, 2019; Sloboda etal., 1996). In a later meta-analysis, Platz etal. (2014) identified a strong correlation [rc = 0.61; 95% CI (0.54, 0.67)] between performance improvement and the quality and quantity of practice, further reinforcing the importance of deliberate and effortful practice inputs. More recently, Passarotto etal. (2022) developed the Deliberate Practice in Music Inventory (DPMI), a novel tool that measures the quality of practice across various musical genres and expertise levels quantitatively. The positive results obtained from the DPMI test confirm the broad effectiveness of deliberate practice in substantially enhancing musical expertise. Individual differences, such as innate capacity or talent (Ericsson and Harwell, 2019; Macnamara etal., 2014), as well as the vividness of mental representation and the ability to manipulate imagery content (Highben and Palmer, 2004), have been argued to contribute to the acquisition of expertise. However, to advance oneself as a selfimproving artist, voluntarily imagining the desired performance in vivid detail and aligning it with performance action has been commonly agreed upon as a necessary element of deliberate practice (Ericsson, 1998; Ericsson and Harwell, 2019; Lehmann and Ericsson, 1997). As such, Ericsson (1998) presented a VMI application model that included three specific roles of musical imagery in representing performance (see Figure1): (a) the imagery of the desired musical sound as the performance goal, (b) the imagery of the motor performance executions, (c) the imagery of the evaluation in terms of the performance (also see Lehmann and Ericsson, 1997). Specifically, the first imagery is the ideal auditory image of the music, representing the performance goal that musicians want to achieve in their practice sessions. The second representation involves motor imagery, focusing on the physical action needed to execute the instrument and meet the performance goals. The third representation entails the real-time assessment of the musician’s current performance compared to the intended goal. Within this process, VMI is integral to forming the mental content of deliberate practice. It enables both student and expert musicians to mentally simulate musical pieces without external stimuli; musicians thus can ‘hear’ music in the absence of sound (Brodsky etal., 2003; Lotze, 2013). However, the efficacy of this practice depends to a large degree on the vividness with which an individual can imagine the music (Lotze, 2013; Aleman etal., 2000). Moreover, VMI facilitates the mental rehearsal of physical actions necessary for performance, strengthening the engaged neural pathways associated with these movements. This process not only aids in the biological planning of movement sequences but also reduces the physical exertion required in actual performances, thereby enhancing overall musical execution (Keller and Appel, 2010). In comparison to physical practice alone, the application of VMI enables musicians to visualize the expected performance and monitor their ongoing performance mentally (Ericsson, 1998). 4.1.2 Self-regulation learning theory For decades, self-regulation learning (SRL) theory has been extensively studied and validated by researchers as an effective framework for facilitating musical learning (Leon-Guerrero, 2008; Nielsen, 2001; Schunk and Zimmerman, 2009; Varela etal., 2016). Initially, the concept of SRL was constructed into three key FIGURE1 Imagery-perception loop mediates expert music performance. Adapted from (Ericsson, 1998). Meng and Luck 10.3389/fpsyg.2024.1452179 Frontiers in Psychology 07 frontiersin.org components from a social-cognitive perspective. These include the strategic selection of learning processes, the implementation of strategies aimed at achieving academic goals based on self-efficacy beliefs, and a dedication to academic aspirations (Zimmerman, 1989, 1990). The early framework of SRL portrayed it as a deliberate, intentional act of acquiring knowledge or skills. This process involves a triadic relationship between the individual, their behavior, and the environment (see Zimmerman, 1989, for more details). Researchers have found that self-regulated learners not only employ various strategies but also understand how these strategies impact their learning outcomes. This understanding underscores that SRL involves a dynamic interaction between cognitive, emotional, and physical elements (Zimmerman, 1990, 2000). Contemporary views of SRL describe it not just as a learning technique, but as a cyclical model of mental self-regulation that supports lifelong learning. This model comprises three phases: the forethought phase, which involves task setting and motivational arousal; the performance phase, which focuses on individual control and ongoing selfmonitoring; and the self-reflection phase, which includes evaluations and emotional assessments of the learning process (Panadero, 2017; Zimmerman, 2000). Within these phases, the use of voluntary imagery plays a crucial role in self-control during the performance phase (Figure2). Zimmerman (2002) describes the application of imagery as a mnemonic strategy. This technique involves mentally linking new knowledge with previous understanding. For instance, when studying the Spanish word “pan” as “bread,” a student may create an image of “bread pan” to enhance comprehension. In this condition, imagery serves as a tool to bridge new information with familiar image concepts, which could positively impact the learning process. In the context of music practice, Renwick and McPherson (2002) discovered that a clarinetist, while engaging in the SRL cycle to master new pieces, voluntarily visualized her tutor’s performance as a reference to assess her own pitch accuracy during practice. Via an analysis of over 300 surveys from music grade exam instrumental candidates, McCormick and McPherson (2003) suggested that using musical imagery as part of SRL can enhance self-efficacy, which in turn, is likely to improve performance quality. In a related study, Clark and Williamon (2011) conducted a nine-week mental skills training program for conservatory-level students, based on the SRL framework. The program included techniques in mental rehearsal, performance preparation, goal-setting, relaxation, motivation, and arousal control. The students who underwent this training showed notable improvements in self-efficacy, self-awareness, and practice duration compared to those in the control group. Moreover, students who engaged in SRL training reported more frequent and vivid use of imagery in their practice routine and rehearsal (Hatfield, 2016). While FIGURE2 Self-Regulation Process. Adapted from (Zimmerman, 2002). Meng and Luck 10.3389/fpsyg.2024.1452179 Frontiers in Psychology 08 frontiersin.org these findings underscore the benefits of incorporating intentional musical imagery into SRL, how imagery interacts with the components of SRL and to what extent these improvements are solely attributable to the use of VMI is still unclear. In essence, while the deliberate use of musical imagery in selfregulated practice is only one part of the broader SRL cycle, its importance cannot be underestimated. As a cognitive strategy, it enhances the integration of new information with existing knowledge. Furthermore, it plays a critical role in managing focus and emotional states, which are crucial for effective and efficient practice (LópezÍñiguez and McPherson, 2024; McPherson etal., 2017). Given its significance, future research should focus on optimizing the use of imagery specifically within music practice, leading to more nuanced and effective SRL methodologies tailored to the unique demands of music learners. 4.1.3 Comparative discussion Despite the theories of DP and SRL being embedded in distinct conceptual grounds, three commonalities are apparent when applied to the context of music practice, particularly in relation to VMI. First, both theoretical models highlight the critical role of VMI in enhancing musicianship by requiring musicians to mentally rehearse complex compositions, improving their execution and deepening their interpretative skills. Second, the emphasis on task-setting and goaloriented exercises within DP resonates with the strategic execution of learning strategies in SRL. The significance of deliberately employing musical imagery to present or sustain the desired goal/task vividly to assist skill acquisition is highlighted in both (Cotter, 2019). Third, both theories recognize the value of self-monitoring and regulation in the learning process, where the use of VMI enables musicians to assess their performance against desired outcomes, thereby enabling adjustments and improvements. Despite these commonalities, each theory differs in its primary focus and application. For example, DP is centered around the accumulation of expertise through extensive, effortful practice, with VMI serving as a tool to present and anticipate the performance specifics. On the other hand, SRL presents a more comprehensive learning model that incorporates cognitive, behavioral, and contextual elements. Within this model, VMI is particularly associated with enhancing memorization and regulating emotions. As both theories share a similar commitment to fostering long-term autonomous learning ability (Ericsson, 1998; Zimmerman, 2002), further longitudinal studies illustrating the effects and efficacy regarding musical expertise development in the DP and SRL approaches, especially the role of VMI over the long term, would beof great benefit. 4.2 Voluntary musical imagery in mental practice 4.2.1 Effect of VMI on mental practice Mental practice (MP) has been well recognized as a means of enhancement that offers extensive benefits for performers in fields like sports (Maring, 1990), music (Coffman, 1990), and surgery (Conlin etal., 2016). In music research, MP refers to the training strategy in which musicians mentally “create or recreate an experience that is similar to a given physical event” (Connolly and Williamon, 2012, p.224) in the absence of overt muscular motions (Driskell etal., 1994; Highben and Palmer, 2004). This technique has been proven to benefit musicians by enhancing learning efficiency (Coffman, 1990; Lim and Lippman, 1991), increasing practice motivation (Clark and Williamon, 2011), and reducing performance anxiety (Hoffman and Hanrahan, 2012). When engaging in MP, the application of VMI proves crucial. This necessity arises because MP tasks require participants to visualize musical notes and their execution in the mind, a process fundamentally reliant on VMI (e.g., Ross, 1985; Bernardi etal., 2012). For instance, early research by Rubin-Rabson (1941) identified the beneficial effects of combining mental practice with physical training on music memorization. In this study, participants were tasked with a mental practice section of the piano notes and kept the mental image as vivid as possible. Subsequent research further investigated whether specific imagery content may have an effect on mental practice efficacy. Highben and Palmer (2004) conducted studies on aural and finger sequence discrimination with pianists to assess the impacts of auditory and motor imagery. Their data indicated that, despite individual differences in imagery ability, the auditory aspect of VMI is more crucial for ensuring music memory. Expanding on previous research, Brown and Palmer (2013) studied how VMI influences formally trained pianists’ encoding and retrieval of novel melodies. They found that both auditory and motor imagery improve the recall of pitch accuracy. However, a well-developed auditory imagery capability is particularly effective at enhancing musicians’ accuracy in pitch sequence learning and ensuring consistent temporal control during performance recall. This suggests that auditory imagery should be a primary focus in the development of musical imagery memorization strategies. Moreover, Brown and Palmer (2013) noted that advanced pianists benefit significantly from employing a feedforward approach using auditory imagery. This strategy involves anticipating and mentally rehearsing the motor sequences necessary for performance, rather than relying solely on feedback from actual auditory inputs during the performance. This proactive use of VMI allows musicians to better prepare and execute their performances (Bernardi etal., 2013; Keller, 2012). Comparative studies of solely physical practice (PP), MP only, or a combination of both have further highlighted the practical efficacy of VMI. These studies indicate that although PP is the most effective method for learning and memorization, integrating MP into PP can yield comparable effectiveness to PP alone while offering additional advantages. Evidence has suggested that by mentally rehearsing music, trombone students can develop a deeper understanding and more accurate anticipation of the works they are studying (Ross, 1985). This combination approach also enhances the retention of musical notation and performance details (Iorio et al., 2022). Furthermore, incorporating MP into PP optimizes musicians’ practice time and reduces their necessity for extensive physical rehearsal, thereby reducing the risks associated with over-practicing (Bernardi etal., 2012). Additionally, MP enhanced with auditory input, such as background recording (Lim and Lippman, 1991) or verbal singing (Steenstrup etal., 2021), is more effective than MP alone, and dividing imagery content into segments or starting with simple tasks may provide more productive benefits for the advancement of mental practice (Cahn, 2008). It’s worth pointing out that, across all skill levels (i.e., professional and amateur), musicians who engage in some form of practice prove superior to those who do not practice at all (i.e., PP only ≥ MP + PP > MP with recording > MP only > no practice; Ross,